Table 1.

Experimental and calculated Bi−P atomic distances (d, Å), interaction energy of the Bi−P interaction (ΔE _int, kcal mol⁻¹), Wiberg bond indices (WBI, −), NPA charges (q, electron) and net charge donation from the ligand to the BiX₃ moiety (Δq calculated as the sum of partial NPA charges in the ligand fragment) at the ωB97XD/cc‐pVDZ(‐PP) level of theory. The partial NPA charge at the P centre in the free ligand 1 is 0.833 e. Properties at the bond critical point: electron density (ρ _bcp, a.u.), Laplacian of the electron density (▿² ρ _bcp, a.u.), η=|λ ₁|/λ ₃ where λ ₁ and λ ₃ are the smallest and largest eigenvalues of the electron density Hessian matrix, respectively, total energy density (H, a.u.), ratio of potential and kinetic energy density (|V|/G, −).

	2 a	2 b	2 c
d(Bi−P)exp	3.365(1)	3.759(7)	3.792(9)
d(Bi−P)calc	3.576	3.631	3.732
ΔE int	8.8	8.0	7.1
WBI (Bi−P)	0.085	0.077	0.062
q(P)	0.838	0.840	0.839
q(Bi)	1.360	1.146	0.847
Δq	0.326	0.332	0.306
ρ bcp	0.0131	0.0121	0.0103
▿2 ρ bcp	0.0267	0.0244	0.0207
η	0.191	0.188	0.182
H	6.2×10−4	6.5×10−4	6.4×10−4
|V|/G	0.897	0.881	0.859